1. The general method of air conditioners for air conditioner failure analysis consists of refrigeration and electrical systems, whose operational status is closely related to the working environment and conditions, so that failure analysis of air conditioners requires integrated consideration. The causes of failure can be classified into two categories: extra-machine causes or man-made malfunctions (especially the normality of the power supply) and internal malfunctions. In the analysis of the treatment of malfunctions, off-site causes should first be eliminated. After removing the in-flight factors, internal malfunctions can be classified into refrigeration system failures and electrical system failures, which should normally be eliminated first. In the case of electrical system malfunctions, the following can also be found: whether the switch power delivers the power; and whether the motor circuit is normal. Along the lines of the above-mentioned general analysis, the range of malfunctions could be gradually reduced and the causes of the malfunctions could be determined. The initial checks of the refrigeration system are conducted by means of questioning, touching, seeing, listening and checking. These methods are simple and effective. Touch: in 20-30 minutes, the compressor is operating, touching the temperature of the straw, exhaust, compressor, evaporation vent, condenser, etc., so that the cooling effect can be judged by the hand. A. Compressors are generally at 90-100°c. B. Surface temperature of evaporation units. The temperature of the working air conditioner evaporation unit should be the same, with cool surfaces, usually at about 15 degrees, and condensed water on the outside of the copper pipe. C. Touch the surface temperature of the condenser. When the air conditioner is running, the condenser will soon warm up, the faster the heat will indicate the faster the cooling, the temperature of the condenser will be around 80 degrees in normal use, and the temperature of the condenser walls will normally be 45-55°c. D. Touching low pressure back to surface temperature. Normal when inhaling pipe cold, vent heat. The coldness of the hand should be felt if the ambient temperature is low and there will be condensed water on the surface of the low-pressure backpipe, if the backpipe is not exposed, if the high-pressure exhaust is hot and the pressurized shell is hot and probably insufficient, and if the compressor's backpipe is fully exposed and closed to half or all of the compressor's casing, it means that the refrigerant is excessive. E. Touch high pressure exhaust temperature. The hand should feel warmer and hotter in the summer. F. Surface temperature of dry filters. Under normal conditions, the hand-dry filter surface feels slightly higher than the ambient temperature. If there is a cold feeling or condensation, there is a slight blockage of dry filters. G. Touch the wind vent temperature. The hand should feel a little chilly, and the length of time it stays cold. See whether the air conditioner is in good shape and whether the parts are working properly. Second, see if the cooling system's pipes are broken, if there's oil trails in the welds and if there's oil trails in the welds, there may be leakage. Take a closer look at whether the plugs in the electrical components are loose, whether the copper tubes are in the right position, and whether the copper tubes touch the shell. Finally, look at whether the lower centrifugal and axle wind is too high and whether the electric motor and compressor have a visible vibration. At 30 degrees, the pressure is about 0. 49 ~ 0. 54 mpa, at 1. 17 ~ 1. 37 mpa, at 35 degrees, at 0. 58 ~ 0. 62 mpa, at 1. 93 mpa, at 43 degrees, at the environment temperature, at 0. 68 mpa. Look at the frost in the low pressure part of the capillary. When normal cooling occurs, at the beginning of the operation of the compressor, the catheters will be thinned with a thin layer of frost, which will then gradually melt down, but there will be a lack of refrigerants or blockage. It is worth noting that the outdoor heat exchangeer works in the heat pump cycle during the winter, which is a low-pressure, low-temperature component and can also cause refrigerant leakage and congestion. If the catheter is exported to the outside heat exchanger entrance, the other parts are dry, indicating that the catheter is half blocked. On the surface, the lack of refrigerants and semi-clogged patterns are consistent. It should also be noted that air conditioners operate with a first look at external working conditions of air conditioners, such as excessive or low indoor, outdoor environment temperatures, dirty filters or poor ventilation, so as to exclude external causes and inappropriate use. Listen: listen carefully to the sound of the whole thing working. When the air conditioner functions, it makes a certain noise, but if it hears some abnormal sound, it is a problem, for example, when the compressor works, there is a “buzz” that can immediately determine that the compressor's motor is not properly activated, and the power should immediately be turned off and the cause should be found; the “ hissing” is the high-pressure flow that occurs after the high-pressure defibration tube in the compressor; the “poll” is the collision of the internal metal of the compressor; and the “when” is the impact of the compressor's spring when it falls or breaks. For an open compressor, a slight and even “twirl” or a small “twirl” of the valve is typically struck; if there is a “twirl” of the compressor, that is, a large volume of refrigerant inhalation of the compressor flight slots with a loose impact; and a “twirl” is a beat after the belt has been damaged. Listening to centrifugal fan and axle fan should be balanced and even, and if you touch or the axis is wrong, there's an abnormal sound. When the system is shut down, when it hears the lightening air flow of "single" (sizing when system pressure is balanced), it is known that the system is virtually unblocked. In addition, other noises can be judged by the hearing, such as: the sound of an axle-flowing fan hitting an iron piece of the outer shell; the “creaking” scream of the wind engine's lack of oil; the “creaking” sound of the wind engine's centrifugal fan and foam shell; the sound of the compressor's base; the sound of a loose horn bolt; the sound of a concussion; and the sound of a fur tube touching the outer shell. Check: generally available pressure tables, semiconductor point thermometers, plier current meters, mass meters, etc. To measure system pressure, temperature, power voltage, insulation resistance, operational current compliance, and halogen detection of leakages of refrigerants. For window-based air conditioners, currents, voltage and resistance are checked with a plier current watch. The current reading should be around the rated current range (with slight variations in temperature and low current). For break-up air conditioners, high and low pressure are also measured by the drt. When the surrounding ambient temperature is around 30°c (under ac cooling), when the pressure of the low pressure table is below 0. 4 mpa, the refrigerant is either insufficient or leaking. The pressure (shel pressure) normal value of the high pressure table should be around 2mpa, and excessive or too low indicates abnormality. If the compressor's exit is blocked, the pressure will rise and the pressure will decrease. The conventional items for inspection and observation are as follows: (1) low pressure pressure; (2) high pressure pressure; (3) balance pressure at shutdown; (4) air intake temperature; (5) vent temperature; (6) compressor temperature; (7) condensers; (8) evaporation; (9) filters; (10) hair catheters; (11) working currents. Analysis: further analysis of the location and magnitude of the failure after reading, touching, hearing and hearing. Since the refrigeration, electrical and air-cycle systems are connected and interact with each other, they need to be analysed in an integrated manner, and the physical parts of the malfunction should be determined from the surface and from the inside, and remain conscious. In case of negligence, there is error of judgement and unnecessary loss. The reasons for the external failure of the non-air conditioner itself include power and other aspects, as follows: (1) power problem 1 power pressure cannot be too low. Usually when the voltage is 15% lower than the normal voltage of 220 v, the compressor of the air conditioner is difficult to activate. When air conditioners operate, the voltage is generally guaranteed above 198 v. The fuses in the dedicated circuits for 2 air conditioners are burned because of their small capacity, or because they are too large and do not provide protective protection, the power plugs are poorly exposed, and the fuse capacity is too small. Three power lines cannot be too small. The excess of household appliances in the 4 air conditioner rooms and the insufficient capacity of the power lines were not allowed. In some parts of the region, low grid voltage and high inaccessibility, especially when electrical equipment, such as high power motors, is used near air conditioners units, often results in excessive voltage fluctuations. The power supply sector has been temporarily out of power or has been in a state of emergency. (2) installation, environment and use of air conditioner 1 has pre- and post-constructive barriers that affect air flow and reduce heat exchange efficiency, thereby reducing the cooling of air conditioner. The temperature in the two rooms is too high or too low, exceeding the permitted temperature range of the air conditioner. 3 air conditioner rooms are not closed, doors and windows are not closed, and access is frequent. The heating equipment is used in 4 rooms, with direct sunlight exposure to air conditioners and ambient temperatures above 43°c. Five condensers drop sharply in the vent and in the vent, even exceeding the actual load of the compressor. Owing to the change in the state of the throttle, the evaporation area is of a certain degree and the temperature of the inhaler rises, in this vicious circle, the compressor breaks off, or the shaking stops. Air conditioner 6 rooms are too large or too high, and air conditioner specifications are too low。the air-contaminated, dusty rooms of the 7 air-conditioning units have caused the air-filtration network to be covered with dust, stains, obstruction of indoor air circulation and thermal exchange. The installation requirements are not met if the window air conditioner is installed in too low and too high a location. 4. The failure of the refrigeration system is judged on the basis of the pressure, temperature and current of the system at the time of operation of the air conditioner by applying the theoretical knowledge of the refrigeration system and carefully observing the various parts of the system before making the correct findings. (b) low pressure (environmental 30°c) 0. 45-5. 5 kg below normal pressure (normal pressure)
